U.S. patent application number 11/898772 was filed with the patent office on 2008-04-24 for game apparatus, wireless module and game system.
Invention is credited to Masato Kuwahara, Shoya Tanaka.
Application Number | 20080096662 11/898772 |
Document ID | / |
Family ID | 39203206 |
Filed Date | 2008-04-24 |
United States Patent
Application |
20080096662 |
Kind Code |
A1 |
Kuwahara; Masato ; et
al. |
April 24, 2008 |
Game apparatus, wireless module and game system
Abstract
A master wireless module transmits a beacon signal to a client
wireless module in the same cycle as a game processing cycle. Each
of the master wireless module and the client wireless module
outputs an interrupt signal when a transmission time of the beacon
signal arrives. A game processing section of each of the master
wireless module and the client wireless module adjusts a V counter
based on the interrupt signal. Therefore, it becomes possible to
easily synchronize, when a multiplayer gameplay is performed using
a plurality of game apparatuses capable of performing wireless
communication with each other, times at which the plurality of game
apparatuses execute predetermined processes.
Inventors: |
Kuwahara; Masato;
(Kyoto-shi, JP) ; Tanaka; Shoya; (Kyoto-shi,
JP) |
Correspondence
Address: |
NIXON & VANDERHYE, P.C.
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
39203206 |
Appl. No.: |
11/898772 |
Filed: |
September 14, 2007 |
Current U.S.
Class: |
463/41 |
Current CPC
Class: |
A63F 13/327 20140902;
A63F 13/45 20140902; A63F 13/77 20140902; A63F 13/34 20140902; H04W
56/00 20130101; A63F 13/31 20140902 |
Class at
Publication: |
463/041 |
International
Class: |
A63F 9/24 20060101
A63F009/24 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2006 |
JP |
2006-285379 |
Claims
1. A game apparatus which realizes a multiplayer gameplay using the
game apparatus and at least one other game apparatus capable of
performing wireless communication with each other, comprising: a
wireless module having a time synchronization function of
synchronizing a timer provided inside the wireless module to
another timer provided inside another wireless module of the at
least one other game apparatus which is set as a communication
party for the multiplayer gameplay; a processing section for
executing a predetermined process; and an adjustment section for
adjusting a time at which the processing section executes the
predetermined process based on a value of the timer of the wireless
module of the game apparatus.
2. The game apparatus according to claim 1, wherein the processing
section executes a process of generating image data and storing the
image data in a display buffer, and the game apparatus further
includes an output section for outputting the image data stored in
the display buffer to a display section, and the adjustment section
adjusts a time at which the output section outputs the image data
to the display section based on the value of the timer of the
wireless module of the game apparatus.
3. The game apparatus according to claim 1, wherein the processing
section executes a process of generating image data and storing the
image data in a display buffer, and the game apparatus further
includes an output section for outputting the image data stored in
the display buffer, and the adjustment section adjusts a time at
which the processing section updates the image data stored in the
display buffer based on the value of the timer of the wireless
module of the game apparatus.
4. The game apparatus according to claim 1, wherein the processing
section executes a process of generating image data and storing the
image data in either of at least two display buffers, and the game
apparatus further includes an output section for outputting the
image data stored in either of the at least two display buffers to
a display section, and the adjustment section adjusts a time at
which the at least two display buffers used by the output section
are switched between each other based on the value of the timer of
the wireless module of the game apparatus.
5. The game apparatus according to claim 1, wherein the processing
section repeatedly executes game processing of one unit, which
processing defines a predetermined procedure, and the adjustment
section adjusts a time at which the processing section executes the
game processing of one unit based on the value of the timer of the
wireless module of the game apparatus.
6. The game apparatus according to claim 1, further comprising an
input section operated by a player, wherein the processing section
executes the predetermined process based on operation information
inputted to the input section, and the adjustment section adjusts a
time at which the predetermined process, which is executed by the
processing section based on the operation information, is executed
based on the value of the timer of the wireless module of the game
apparatus.
7. The game apparatus according to claim 6, wherein the wireless
module determines a time at which the operation information is
exchanged with the at least one other game apparatus based on the
value of the timer.
8. The game apparatus according to claim 1, further comprising a
counter for measuring a processing cycle, wherein the processing
section executes the predetermined process in a cyclic manner based
on a value of the counter, and the adjustment section adjusts the
value of the counter based on the value of the timer of the
wireless module of the game apparatus.
9. The game apparatus according to claim 1, wherein the wireless
module includes interrupt signal outputting means of outputting an
interrupt signal in a constant cycle based on the value of the
timer, and the adjustment section adjusts a time at which the
predetermined process is executed based on a time at which the
wireless module outputs the interrupt signal.
10. The game apparatus according to claim 9, further comprising a
counter for measuring a processing cycle, wherein the processing
section executes the predetermined process in a predetermined cycle
based on a value of the counter, the interrupt signal outputting
means outputs the interrupt signal in the predetermined cycle based
on the value of the timer, and the adjustment section adjusts the
value of the counter such that the value of the counter obtained
when the wireless module outputs the interrupt signal becomes close
to a predetermined fixed value.
11. The game apparatus according to claim 9, wherein the wireless
module transmits a beacon signal to the said another wireless
module, and includes beacon interval setting means of setting a
cycle of the beacon signal transmitted from the wireless module to
a constant cycle, and the interrupt signal outputting means outputs
the interrupt signal when a transmission time of the beacon signal
arrives.
12. The game apparatus according to claim 1, wherein the processing
section repeatedly executes the predetermined process based on data
necessary for game processing, which is received from the said
another wireless module in a constant cycle, and includes beacon
interval setting means of setting a cycle of a beacon signal
transmitted by the wireless module to the constant cycle, and the
wireless module transmits the beacon signal in a constant cycle
based on the value of the timer, and transmits or receives the data
necessary for the game processing to or from the said another
wireless module each time the wireless module transmits the beacon
signal to the said another wireless module, and the adjustment
section adjusts the time at which the processing section executes
the predetermined process based on a transmission time of the
beacon signal, which is obtained based on the value of the timer of
the wireless module of the game apparatus.
13. The game apparatus according to claim 12, further comprising an
input section operated by a player, wherein the processing section
repeatedly executes the predetermined process based on operation
information inputted to an input section of the game apparatus and
the operation information inputted to another input section of the
at least one other game apparatus, and the wireless module
exchanges the operation information with the at least one other
game apparatus each time the wireless module transmits the beacon
signal to the said another wireless module.
14. The game apparatus according to claim 12, wherein the wireless
module further includes interrupt signal outputting means of
outputting the interrupt signal based on the value of the timer,
when the transmission time of the beacon signal arrives, and the
adjustment section adjusts a time at which the predetermined
process is executed based on a time at which the wireless module
outputs an interrupt signal.
15. The game apparatus according to claim 14, wherein the wireless
module transmits or receives the data necessary for the game
processing to or from the said another wireless module after
transmitting the beacon signal to the said another wireless module,
and further includes a sleep function of operating in a sleep mode
until the transmission time of the beacon signal subsequently
arrives after transmitting or receiving the data necessary for the
game processing to or from the said another wireless module.
16. The game apparatus according to claim 1, wherein the processing
section reads the value of the timer of the wireless module in a
constant cycle, and adjusts the time at which the processing
section executes the predetermined process based on the read
value.
17. The game apparatus according to claim 16, wherein the
processing section repeatedly executes game processing of one unit,
which processing defines a predetermined procedure, and reads the
value of the timer of the wireless module in a cycle N times (N is
a natural number) as long as the game processing of one unit.
18. The game apparatus according to claim 1, wherein the wireless
module synchronizes the timer provided inside the wireless module
to the said another timer provided inside the said another wireless
module of the at least one other game apparatus based on an
IEEE802.11 standard.
19. A game apparatus which realizes a multiplayer gameplay using
the game apparatus and at least one other game apparatus capable of
performing wireless communication with each other, comprising: a
wireless module having a time synchronization function of
synchronizing a timer provided inside the wireless module to
another timer provided inside another wireless module of the at
least one other game apparatus which is set as a communication
party for the multiplayer gameplay; a processing section for
executing a predetermined process; and a determination section for
determining a time at which the processing section executes the
predetermined process based on a value of the timer of the wireless
module of the game apparatus.
20. A game apparatus which realizes a multiplayer gameplay using
the game apparatus and at least one other game apparatus capable of
performing wireless communication with each other, comprising: a
connector connectable to a wireless module having a time
synchronization function of synchronizing a timer provided inside
the wireless module to another timer provided inside another
wireless module of the at least one other game apparatus which is
set as a communication party for the multiplayer gameplay; a
processing section for executing a predetermined process; an
adjustment section for adjusting a time at which the processing
section executes the predetermined process based on the value of
the timer of the wireless module connected to the connector.
21. A wireless module which realizes a multiplayer gameplay using a
game apparatus and at least one other game apparatus, comprising:
time synchronization means of synchronizing a timer provided inside
the wireless module to another timer provided inside another
wireless module; and interrupt signal outputting means of
outputting an interrupt signal in a constant cycle based on a value
of the timer.
22. A game system which realizes a multiplayer gameplay using a
plurality of game apparatuses including at least a first game
apparatus and a second game apparatus, all of which are capable of
performing wireless communication with each other, the first game
apparatus including: a first wireless module having a time
synchronization function of synchronizing a timer provided inside
the first wireless module to another timer provided inside a second
wireless module of the second game apparatus; a first processing
section for executing a predetermined process; and a first
adjustment section for adjusting a time at which the first
processing section executes the predetermined process based on a
value of the timer of the first wireless module, and the second
game apparatus including: the second wireless module having the
time synchronization function of synchronizing the said another
timer provided inside the second wireless module to the timer
provided inside the first wireless module of the first game
apparatus; a second processing section for executing a
predetermined process; and a second adjustment section for
adjusting a time at which the second processing section executes
the predetermined process based on a value of the said another
timer of the second wireless module.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The disclosure of Japanese Patent Application No.
2006-285379, filed Oct. 19, 2006, is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a game apparatus, a
wireless module and a game system, and more particularly to a game
apparatus, a wireless module and a game system capable of realizing
a multiplayer gameplay using a plurality of game apparatuses
capable of performing wireless communication with each other.
[0004] 2. Description of the Background Art
[0005] Conventionally, there is a technique in which other game
apparatuses each adjusts a transmission time of a signal based on a
reception time of a signal transmitted from a reference game
apparatus (Japanese Laid-Open Patent Publication No. 2000-135380
(hereinafter referred to as "patent document 1"), for example).
[0006] Conventionally, there is also a technique in which a master
game apparatus transmits time information indicating a specific
time to a client game apparatus, and the client game apparatus
adjusts a game processing cycle based on the received time
information (Japanese Laid-Open Patent Publication No. 2005-261856
(hereinafter referred to as "patent document 2"), for example).
[0007] Conventionally, there is also a technique in which a master
game apparatus transmits a reset command to a client game apparatus
in a constant cycle, and the client game apparatus resets a
synchronization counter in response to the received reset command
(Japanese Laid-Open patent Publication No. 8-243255 (hereinafter
referred to as "patent document 3"), for example).
[0008] However, in the technique disclosed in patent document 1,
communication timings are merely adjusted between a plurality of
game apparatuses. With the technique disclosed in patent document 1
only, processing cycles to be executed by the plurality of game
apparatuses cannot be synchronized to each other.
[0009] Furthermore, in the technique disclosed in patent document
2, the master game apparatus needs to transmit the time information
to the client game apparatus on a regular basis, thereby
correspondingly deteriorating a usage efficiency of a communication
line.
[0010] Still furthermore, the technique disclosed in patent
document 3 is effective only for wired communication. However, in
the case where the technique disclosed in patent document 3 is
applied to wireless communication, problems such as delay and
jitter occur, thereby making it impossible to easily apply the
technique disclosed in patent document 3 to wireless
communication.
SUMMARY OF THE INVENTION
[0011] Therefore, an object of the present invention is to provide
a game apparatus, a wireless module and a game system capable of
easily synchronizing, when performing a multiplayer gameplay using
a plurality of game apparatuses capable of performing wireless
communication with each other, times at which the plurality of game
apparatuses execute predetermined processes.
[0012] The present invention has the following features to attain
the object mentioned above. The reference numerals, step numbers
and the like in the parentheses indicate the correspondence with
the embodiment described below in order to aid in understanding the
present invention and are not intended to limit, in any way, the
scope of the present invention.
[0013] A game apparatus (10a) according to the present invention
which realizes a multiplayer gameplay using the game apparatus
(10a) and at least one other game apparatus (10b) capable of
performing wireless communication with each other, comprises: a
wireless module (12a) having a time synchronization function of
synchronizing a timer (124a) provided inside the wireless module
(12a) to another timer (124b) provided inside another wireless
module (12b) of the at least one other game apparatus (10b) which
is set as a communication party for the multiplayer gameplay; a
processing section (14a, 18a) for executing a predetermined
process; and an adjustment section (14a) for adjusting a time at
which the processing section executes the predetermined process
based on a value of the timer (124a) of the wireless module of the
game apparatus.
[0014] The processing section may execute a process of generating
image data and storing the image data in a display buffer, and the
game apparatus may further include an output section for outputting
the image data stored in the display buffer to a display section,
and the adjustment section may adjust a time at which the output
section outputs the image data to the display section based on the
value of the timer of the wireless module of the game
apparatus.
[0015] The processing section may execute a process of generating
image data and storing the image data in a display buffer, and the
game apparatus may further include an output section for outputting
the image data stored in the display buffer, and the adjustment
section may adjust a time at which the processing section updates
the image data stored in the display buffer based on the value of
the timer of the wireless module of the game apparatus.
[0016] The processing section may execute a process of generating
image data and storing the image data in either of at least two
display buffers, and the game apparatus may further include an
output section for outputting the image data stored in either of
the at least two display buffers to a display section, and the
adjustment section may adjust a time at which the at least two
display buffers used by the output section are switched between
each other based on the value of the timer of the wireless module
of the game apparatus.
[0017] The processing section may repeatedly execute game
processing of one unit, which processing defines a predetermined
procedure, and the adjustment section may adjust a time at which
the processing section executes the game processing of one unit
based on the value of the timer of the wireless module of the game
apparatus.
[0018] The game apparatus may further comprise an input section
operated by a player, wherein the processing section may execute
the predetermined process based on operation information inputted
to the input section, and the adjustment section may adjust a time
at which the predetermined process, which is executed by the
processing section based on the operation information, is executed
based on the value of the timer of the wireless module of the game
apparatus.
[0019] The wireless module may determine a time at which the
operation information is exchanged with the at least one other game
apparatus based on the value of the timer.
[0020] The game apparatus may further comprise a counter for
measuring a processing cycle, wherein the processing section may
execute the predetermined process in a cyclic manner based on a
value of the counter, and the adjustment section may adjust the
value of the counter based on the value of the timer of the
wireless module of the game apparatus.
[0021] The wireless module may include interrupt signal outputting
means of outputting an interrupt signal in a constant cycle based
on the value of the timer, and the adjustment section may adjust a
time at which the predetermined process is executed based on a time
at which the wireless module outputs the interrupt signal. Thus, a
change in the value of the timer included in the wireless module
can be minimized.
[0022] The game apparatus may further comprise a counter for
measuring a processing cycle, wherein the processing section may
execute the predetermined process in a predetermined cycle based on
a value of the counter, the interrupt signal outputting means may
output the interrupt signal in the predetermined cycle based on the
value of the timer, and the adjustment section may adjust the value
of the counter such that the value of the counter obtained when the
wireless module outputs the interrupt signal becomes close to a
predetermined fixed value.
[0023] The wireless module may transmit a beacon signal to the said
another wireless module, and include beacon interval setting means
of setting a cycle of the beacon signal transmitted from the
wireless module to a constant cycle, and the interrupt signal
outputting means may output the interrupt signal when a
transmission time of the beacon signal (a reception time of the
beacon signal for the said another module acting as a client)
arrives.
[0024] The processing section may repeatedly execute the
predetermined process based on data necessary for game processing,
which is received from the said another wireless module in a
constant cycle, and include beacon interval setting means of
setting a cycle of a beacon signal transmitted by the wireless
module to the constant cycle, and the wireless module may transmit
the beacon signal in a constant cycle based on the value of the
timer, and transmit or receive the data necessary for the game
processing to or from the said another wireless module each time
the wireless module transmits the beacon signal to the said another
wireless module, and the adjustment section may adjust the time at
which the processing section executes the predetermined process
based on a transmission time of the beacon signal, which is
obtained based on the value of the timer of the wireless module of
the game apparatus.
[0025] The game apparatus may further comprise an input section
operated by a player, wherein the processing section may repeatedly
execute the predetermined process based on operation information
inputted to an input section of the game apparatus and the
operation information inputted to another input section of the at
least one other game apparatus, and the wireless module may
exchange the operation information with the at least one other game
apparatus each time the wireless module transmits the beacon signal
to the said another wireless module.
[0026] The wireless module may further include interrupt signal
outputting means of outputting the interrupt signal based on the
value of the timer, when the transmission time of the beacon signal
arrives, and the adjustment section may adjust a time at which the
predetermined process is executed based on a time at which the
wireless module outputs an interrupt signal.
[0027] The wireless module may transmit or receive the data
necessary for the game processing to or from the said another
wireless module after transmitting the beacon signal to the said
another wireless module, and further include a sleep function of
operating in a sleep mode until the transmission time of the beacon
signal subsequently arrives after transmitting or receiving the
data necessary for the game processing to or from the said another
wireless module.
[0028] The processing section may read the value of the timer of
the wireless module in a constant cycle, and adjust the time at
which the processing section executes the predetermined process
based on the read value.
[0029] The processing section may repeatedly execute game
processing of one unit, which processing defines a predetermined
procedure, and read the value of the timer of the wireless module
in a cycle N times (N is a natural number) as long as the game
processing of one unit.
[0030] The wireless module may synchronize the timer provided
inside the wireless module to the said another timer provided
inside the said another wireless module of the at least one other
game apparatus based on an IEEE802.11 standard.
[0031] Another game apparatus (10a) according to the present
invention which realizes a multiplayer gameplay using the game
apparatus (10a) and at least one other game apparatus (10b) capable
of performing wireless communication with each other, comprises: a
wireless module (12a) having a time synchronization function of
synchronizing a timer (124a) provided inside the wireless module
(12a) to another timer (124b) provided inside another wireless
module (12b) of the at least one other game apparatus (10b) which
is set as a communication party for the multiplayer gameplay; a
processing section (14a, 18a) for executing a predetermined
process; and a determination section (14a) for determining a time
at which the processing section executes the predetermined process
based on a value of the timer (124a) of the wireless module of the
game apparatus.
[0032] Still another game apparatus (10a) according to the present
invention which realizes a multiplayer gameplay using the game
apparatus (10a) and at least one other game apparatus (10b) capable
of performing wireless communication with each other, comprises: a
connector (not shown) connectable to a wireless module (12a) having
a time synchronization function of synchronizing a timer (124a)
provided inside the wireless module (12a) to another timer (124b)
provided inside another wireless module (12b) of the at least one
other game apparatus (10b) which is set as a communication party
for the multiplayer gameplay; a processing section (14a, 18a) for
executing a predetermined process; an adjustment section (14a) for
adjusting a time at which the processing section executes the
predetermined process based on the value of the timer (124a) of the
wireless module connected to the connector.
[0033] A wireless module (12a) according to the present invention
which realizes a multiplayer gameplay using a game apparatus (10a)
and at least one other game apparatus (10b), comprises: time
synchronization means (123a) of synchronizing a timer (124a)
provided inside the wireless module (12a) to another timer (124b)
provided inside another wireless module (12b); and interrupt signal
outputting means (123a) of outputting an interrupt signal in a
constant cycle based on a value of the timer (124a).
[0034] A game system according to the present invention is a game
system which realizes a multiplayer game play using a plurality of
game apparatuses including at least a first game apparatus (10a)
and a second game apparatus (10b), all of which are capable of
performing wireless communication with each other. The first game
apparatus includes: a first wireless module (12a) having a time
synchronization function of synchronizing a timer (124a) provided
inside the first wireless module (12a) to another timer (124b)
provided inside a second wireless module (12b) of the second game
apparatus; a first processing section (14a, 18a) for executing a
predetermined process; and a first adjustment section (14a) for
adjusting a time at which the first processing section executes the
predetermined process based on a value of the timer (124a) of the
first wireless module. The second game apparatus includes: the
second wireless module having the time synchronization function of
synchronizing the said another timer provided inside the second
wireless module to the timer provided inside the first wireless
module of the first game apparatus; a second processing section
(14b, 18b) for executing a predetermined process; and a second
adjustment section (14b) for adjusting a time at which the second
processing section executes the predetermined process based on a
value of the said another timer (124b) of the second wireless
module.
[0035] According to the present invention, it becomes possible to
easily synchronize, when performing the multiplayer gameplay using
a plurality of game apparatuses capable of performing wireless
communication with each other, times at which the plurality of game
apparatuses execute the predetermined processes.
[0036] These and other objects, features, aspects and advantages of
the present invention will become more apparent from the following
detailed description of the present invention when taken in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a block diagram illustrating a configuration of a
game system according to a first embodiment of the present
invention;
[0038] FIG. 2 is a sequence diagram illustrating an operation of
the game system according to the first embodiment of the present
invention;
[0039] FIG. 3 is diagram illustrating a corresponding relationship
between a display screen and a value of a V counter 181a;
[0040] FIG. 4 is a flowchart illustrating a flow of a process
executed by a wireless module 12a and a wireless module 12b
according to the first embodiment of the present invention;
[0041] FIG. 5 is a flowchart illustrating a flow of a main process
executed by a game processing section 14a and a game processing
section 14b according to the first embodiment of the present
invention;
[0042] FIG. 6 is a flowchart illustrating a TBTT interrupt process
executed by the game processing section 14a and the game processing
section 14b according to the first embodiment of the present
invention;
[0043] FIG. 7 is a flowchart illustrating a V blank interrupt
process executed by the game processing section 14a and the game
processing section 14b according to the present invention;
[0044] FIG. 8 is a sequence diagram illustrating a variant of the
operation of the game system according to the first embodiment of
the present invention;
[0045] FIG. 9 is a block diagram illustrating the configuration of
the game system according to a second embodiment of the present
invention;
[0046] FIG. 10 is a sequence diagram illustrating the operation of
the game system according to the second embodiment of the present
invention;
[0047] FIG. 11 is a flowchart illustrating the flow of the process
executed by the wireless module 12a and the wireless module 12b
according to the second embodiment of the present invention;
and
[0048] FIG. 12 is a flowchart illustrating the V blank interrupt
process executed by the game processing section 14a and the game
processing section 14b according to the second embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] Hereinafter, various embodiments of the present invention
will be described.
First Embodiment
[0050] FIG. 1 is a block diagram illustrating a configuration of a
game system according to a first embodiment of the present
invention. Although the present embodiment illustrates an example
where two game apparatuses (i.e., a first game apparatus 10a and a
second game apparatus 10b) perform wireless communication with each
other, the present invention is not limited thereto. The present
invention is applicable to a case where three or more game
apparatuses perform wireless communication with each other.
[0051] The first game apparatus 10a and the second game apparatus
10b are set to each other as communication parties for a
multiplayer gameplay. For example, prior to starting the
multiplayer gameplay, the first game apparatus 10a exchanges its
own apparatus ID (which may be added with a user ID or a game
program ID of a game program executed by the game apparatus 10a)
with the second game apparatus 10b by wireless communication, and
presents information concerning the second game apparatus 10b by
means of an image, sound or the like to a player of the first game
apparatus 10a. Based on the information presented as such, the
player of the first game apparatus 10a determines whether or not to
start the multiplayer gameplay together with a player of the second
game apparatus 10b. If the both players instruct the game
apparatuses 10a and 10b respectively to start the multiplayer
gameplay together with each other via an input section, the first
game apparatus 10a and the second game apparatus 10b are set to
each other as the communication parties for the multiplayer
gameplay.
[0052] The first game apparatus 10a comprises a wireless module
12a, a game processing section 14a, an interrupt circuit 16a, a
display section 18a, a clock 20a, a storage section 24a, a flame
buffer 26a, and an input section 28a. The second game apparatus 10b
has the same configuration as that of the first game apparatus 10a,
and therefore a detailed description of the second game apparatus
10b will be omitted.
[0053] To the first game apparatus 10a, a game cartridge 30a is
connected via a connector 22a. The game cartridge 30a stores a game
program for realizing a game which can be simultaneously played by
a plurality of players performing wireless communication between a
plurality of game apparatuses. The game program is loaded to the
storage section 24a via the connector 22a and executed by the game
processing section 14a. Note that the game program may be supplied
to the storage section 24a from a storage medium other than the
game cartridge 30a such as an optical disc or a magnetic disc, or
from an external computer or other game apparatuses by wired
communication or wireless communication.
[0054] The wireless module 12a has a function of performing
wireless communication with a wireless module 12b of the second
game apparatus 10b in accordance with a communication protocol
which complies with a wireless LAN standard IEEE802.11. Although
the present embodiment illustrates an example where the wireless
module 12a is embedded in the first game apparatus 10a, the present
invention is not limited thereto. The wireless module 12a may be
connected to the first game apparatus 10a via a not shown connector
included in the first game apparatus 10a.
[0055] The wireless module 12a includes a wireless section 121a, a
storage section 122a, a processor 123a, a TSF timer 124a and a
clock 125a. The wireless section 121a converts a baseband signal
outputted from the processor 123a into a wireless signal, and also
receives a wireless signal transmitted from the wireless module 12b
of the second game apparatus 12b and converts the received wireless
signal into a baseband signal. The storage section 122a is used by
the processor 123a for temporarily retaining data. In addition, the
storage section 122a is also used as a transmission/reception
buffer for passing data, which is transmitted and received between
the first game apparatus 10a and the second game apparatus 10b
(i.e., data to be transmitted to the second game apparatus 10b and
data received from the second game apparatus 10b), between the game
processing section 14a and the wireless module 12a. The processor
123a controls wireless communication between the wireless module
12a and the wireless module 12b based on the wireless LAN standard
IEEE802.11. The TSF timer 124a is a timer for measuring a time
period based on a clock signal outputted from the clock 125a
included in the wireless module 12a, and is used for synchronizing
a process executed by the wireless module 12a and a process
executed by the wireless module 12b. A value of the TSF timer 124a
indicates an elapsed time since the TSF timer 124a starts
counting.
[0056] In the present embodiment, it is assumed that the wireless
module 12a operates as a master, and the wireless module 12b
operates as a client. Note that when a plurality of wireless
modules perform communication with each other, any method may be
used for determining one of the wireless modules acting as a
master. Each of the wireless module 12a and the wireless module 12b
has a TSF (Timing Synchronization Function) for synchronizing the
process executed by the wireless module 12a and the process
executed by the wireless module 12b. The wireless module 12a acting
as the master transmits a beacon signal on a regular basis. The
game processing section 14a can set a transmission cycle of the
beacon signal to any cycle (the transmission cycle of the beacon
signal may be fixed). In the present embodiment, the transmission
cycle of the beacon signal is set to 16.7 msec which is the same as
a game processing cycle (i.e., a cycle in which game processing of
one unit, which processing defines a predetermined procedure, is
repeatedly executed, the cycle being 16.7 msec in the present
embodiment) of the game processing section 14a. However, the
transmission cycle of the beacon signal is not limited thereto. The
transmission cycle of the beacon signal may be an integral multiple
of the game processing cycle. The reason therefor will be described
later. The beacon signal includes information about the value of
the TSF timer 124a (hereinafter referred to as a "TSF timer value")
indicating a transmit time of the beacon signal and a beacon
interval (a transmission interval of the beacon signal). A
processor 123b of the wireless module 12b which receives a beacon
signal transmitted from the wireless module 12a changes a value of
a TSF timer 124b so as to become equal to the TSF timer value
included in the received beacon signal as appropriate. As described
above, the value of the TSF timer 124b of the wireless module 12b
is changed as appropriate based on the beacon signal which is
transmitted in a cyclic manner, thereby making it possible to
synchronize the TSF timer 124a of the wireless module 12a and the
TSF timer 124b of the wireless module 12b.
[0057] Since the beacon signal includes the information about the
beacon interval as described above, the wireless module 12b can
recognize a TBTT (Target Beacon Transmit Time) based on the value
of the TSF timer 124b and the information about the beacon
interval. When the TBTT arrives, the wireless module 12a acting as
the master starts an operation of transmitting a beacon signal, and
the wireless module 12b acting as the client starts an operation of
preparing to receive the beacon signal.
[0058] In the present embodiment, as shown in FIG. 2, a beacon
signal is transmitted from the wireless module 12a acting as the
master in a cycle of 16.7 msec, and immediately after the beacon
signal is transmitted, operation information is
transmitted/received between the wireless module 12a acting as the
master and the wireless module 12b acting as the client, in order
to share the operation information (information indicating a
content of an operation inputted to the input section 28 by the
player of each of the game apparatuses) between the first game
apparatus 10a and the second game apparatus 10b. When the
transmission/reception of the operation information is completed,
each of the wireless module 12a and the wireless module 12b
operates in a sleep mode until the TBTT subsequently arrives. When
the TBTT subsequently arrives (to be more precise, immediately
before the TBTT subsequently arrives), each of the wireless module
12a and the wireless module 12b returns to a normal mode from the
sleep mode, and the wireless module 12a starts the operation of
transmitting another beacon signal and the wireless module 12b
starts the operation of preparing to receive the said another
beacon signal. As such, while sharing the operation information
between the first game apparatus 10a and the second game apparatus
10b in a cycle of 16.7 msec, power savings of the wireless module
12a and the wireless module 12b can be achieved.
[0059] Note that it does not necessarily have to be the operation
information which is transmitted/received between the wireless
module 12a and the wireless module 12b. For example, a game
parameter and the like generated by the game processing executed by
each of the game apparatuses 10a and 10b may be
transmitted/received between the wireless modules 12a and 12b.
[0060] Furthermore, it is not necessary for each of the wireless
modules 12a and 12b to be in the sleep mode after
transmitting/receiving the operation information.
[0061] In the present embodiment, when the TBTT arrives, the
processor 123a outputs an interrupt signal (hereinafter referred to
as a TBTT interrupt signal). The same is also true of the processor
123b. The present embodiment assumes that the TBTT interrupt signal
is outputted every twelve times the TBTT arrives. However, a
frequency in which the TBTT interrupt signal is outputted is not
limited thereto. The TBTT interrupt signal may be outputted every N
times (N is a natural number) the TBTT arrives. In this case, a
cycle in which the TBTT interrupt signal is outputted is a cycle N
times as long as the game processing cycle (16.7 msec) of the game
processing section 14a.
[0062] The game processing section 14a executes the game processing
in accordance with the game program stored in the game cartridge
30a. The game processing is executed based on signals outputted
from the input section 28a and the operation information, about the
second game apparatus 10b, which is received by the wireless module
12a (information concerning an operation inputted by a user of the
second game apparatus 10b). The game processing section 14a
generates a game image reflecting a result of the game processing,
and writes image data of the game image into the flame buffer 26a.
The game image is updated in a cycle of 16.7 msec.
[0063] The interrupt circuit 16a outputs the TBTT interrupt signal
outputted from the wireless module 12a and a V blank interrupt
signal outputted from the display section 18a, which is to be
described later, to the game processing section 14a as interrupt
request signals. When any interrupt request signal is outputted
from the interrupt circuit 16a, the game processing section 14a
temporarily suspends the game processing so as to execute a
predetermined interrupt process in response to the interrupt
request signal, and resumes the game processing after the interrupt
process is completed.
[0064] The display section 18a has a display screen, and displays
the game image on the display screen based on the image data
written by the game processing section 14a into the flame buffer
26a. The display screen is updated in a cycle of 16.7 msec. The
display section 18a is typically comprised of a liquid crystal
panel and a display control circuit. The display section 18a has a
V counter 181a, and electrical signals corresponding to the image
data read from the flame buffer 26a are supplied to pixels on a
scanning line corresponding to a value of the V counter 181a. The
value of the V counter 181a is updated at a predetermined interval
based on a clock signal outputted from the clock 20a. The value of
the V counter 181a is reset to "0" after indicating "262".
[0065] In the display section 18a, any pixel of an image displayed
on the display screen is not updated during a time period from when
scanning which is sequentially performed from a top scanning line
of the display screen to a bottom scanning line thereof is
completed to when the scanning is returned to the top scanning line
(hereinafter referred to as a "V blank period"). During the V blank
period, the display section 18a does not access the flame buffer
26a. Thus, the game processing section 14a writes the image data
into the flame buffer 26a during the V blank period, thereby making
it possible to update the image data without distorting the display
image.
[0066] Note that the V counter 181a continues counting even during
the V blank period. In the present embodiment, as shown in FIG. 3,
the value of the V counter 181a obtained when scanning is performed
on the top scanning line of the display screen is "0", the value of
the V counter 181a obtained when the scanning is performed on the
bottom scanning line of the display screen is "191", and the value
of the V counter 181a obtained immediately before the scanning is
performed on the top scanning line of the display screen is "262".
In this case, a time period during which the value of the V counter
181a is within a range from "192" to "262" is the V blank period.
The display section 18a has a function of outputting the V blank
interrupt signal when the V blank period arrives (i.e., when the
value of the V counter 181a becomes "192"). The interrupt circuit
16a which receives the V blank interrupt signal from the display
section 18a transmits a V blank interrupt request signal to the
game processing section 14a. The game processing section 14a starts
writing the image data into the flame buffer 26a in response to the
V blank interrupt request signal, thereby allowing the game
processing section 14a to write the image data into the flame
buffer 26a during the V blank period.
[0067] The storage section 24a is a storage area used by the game
processing section 14a executing the game program.
[0068] The flame buffer 26a is a storage area for temporarily
retaining the image data generated by the game processing section
14a so as to be outputted to the display section 18a.
[0069] The input section 28a is a game controller operated by the
player, and outputs a signal in accordance with an operation
performed by the player.
[0070] In the present embodiment, the game processing section 14a
executes the game processing in the same cycle as that in which the
display section 18a updates the display screen (16.7 msec).
Specifically, a series of processes in which the game processing
section 14a (1) shares the operation information between the first
game apparatus 10a and the second game apparatus 10b, (2) executes
the game processing based on the shared operation information, and
(3) generates the game image reflecting a result of the game
processing and writes the generated image data into the flame
buffer 26a is repeated in a cycle of 16.7 msec.
[0071] In the case where the players of the first game apparatus
10a and the second game apparatus 10b play the multiplayer game by
causing the first game apparatus 10a and the second game apparatus
10b to perform wireless communication with each other, it is
preferable that the game processing cycle of the game processing
section 14a of the first game apparatus 10a coincides with that of
the game processing section 14b of the second game apparatus 10b.
This is because if the game processing cycles between the game
processing sections 14a and 14b are shifted from each other, a game
processing result of the first game apparatus 10a and a game
processing result of the second game apparatus 10b may be
accordingly shifted from each other.
[0072] In the present embodiment, the game processing section 14a
of the first game apparatus 10a adjusts the V counter 181a with
respect to a time at which the wireless module 12a outputs the TBTT
interrupt signal. Similarly, the game processing section 14b of the
second game apparatus 10b adjusts the V counter 181b with respect
to a time at which the wireless module 12b outputs the TBTT
interrupt signal. Hereinafter, an adjustment process executed by
the game processing section 14a adjusting the V counter 181a will
be described in detail.
[0073] In an interrupt process to be executed when the wireless
module 12a outputs the TBTT interrupt signal (hereinafter referred
to as a "TBTT interrupt process"), the game processing section 14a
temporarily stores the value of the V counter 181a obtained when
the TBTT interrupt signal is outputted (hereinafter referred to as
a "V counter value at TBTT" in the storage section 24a.
Furthermore, in another interrupt process to be executed when the
display section 18a outputs the V blank interrupt signal
(hereinafter referred as a "V blank interrupt process"), the game
processing section 14a calculates a difference between the V
counter value at TBTT stored in the storage section 24a and a
predetermined ideal value ("0" in the present embodiment, for
example), thereby increasing or decreasing the value of the V
counter 181a based on the difference such that the value of the V
counter 181a obtained when the TBTT interrupt signal is outputted
becomes close to the predetermined ideal value. For example, when
the V counter value at TBTT is "2", "2" is subtracted from the
value of the V counter 181a. When the V counter value at TBTT is
"260", "3" is added to the value of the V counter 181a. As
described above, the value of the V counter 181a is not changed
when the TBTT interrupt process is executed, but changed when the V
blank interrupt process is executed. This is because the value of
the V counter 181a can be changed during the V blank period. During
the V blank period, the display screen is never distorted even if
the value of the V counter 181a is changed. Only if distortion on
the display screen is allowed, the value of the V counter 181a may
be changed at any time.
[0074] Note that in the case where a certain value is subtracted
from the value of the V counter 181a, the game processing section
14a adjusts the subtracted value of the V counter 181a so as not to
be smaller than the value of the V counter 181a obtained at a time
of V blank interruption ("192" in the present embodiment).
Specifically, in the case where "2" is subtracted from the value of
the V counter 181a, the value of the V counter 181a is not to be
changed until the value of the V counter 181a becomes "195" or
greater. In this case, the subtracted value of the V counter 181a
will be "193" or greater.
[0075] When the difference between the V counter value at TBTT and
the predetermined ideal value is greater than a predetermined value
("4", for example), instead of causing the value of the V counter
181a obtained when the TBTT interrupt signal is outputted to
instantly coincide with the predetermined ideal value, the value of
the V counter 181a may be caused to become close to the
predetermined ideal value gradually in a plurality of stages. This
can be realized, for example, when a range within which the value
of the V counter 181a can be changed at one time is limited from
"-4" to "+4". Thus, even when there is a great difference between
the V counter value at TBTT and the predetermined ideal value, the
game processing cycle can be adjusted without causing the player to
feel awkward.
[0076] On the other hand, when the difference between the V counter
value at TBTT and the predetermined ideal value is smaller than a
predetermined value ("2", for example), a change in the value of
the V counter 181a may be omitted.
[0077] By executing the adjustment process as described above, the
game processing cycle of the game processing section 14a is
synchronized to the TBTT in the wireless module 12a. Similarly, in
the case of the second game apparatus 10b, the game processing
section 14b adjusts the V counter 181b, thereby synchronizing the
game processing cycle of the game processing section 14b to the
TBTT in the wireless module 12b. Here, the TSF allows the TBTT in
the wireless module 12a and the TBTT in the wireless module 12b to
be synchronized to each other. As a result, the game processing
cycle of the game processing section 14a and the game processing
cycle of the game processing section 14b are also synchronized to
each other accordingly.
[0078] Hereinafter, described will be flows of processes executed
by the game processing section 14a, the game processing section
14b, the wireless module 12a and the wireless module 12b when
executing the game in accordance with the game program loaded to
the storage section 24a (the storage section 24b) from the game
cartridge 30a (the game cartridge 30b).
[0079] With reference to a flowchart shown in FIG. 4, the flow of
the process executed by the wireless module 12a and the wireless
module 12b will be firstly described.
[0080] In step S10, the processor 123a of the wireless module 12a
acting as the master outputs a beacon signal via the wireless
section 121a. The beacon signal includes the value of TSF timer
124a obtained at a transmit time of the beacon signal and the
information about the beacon interval set by the game processing
section 14a.
[0081] In step S12, based on the value of the TSF timer 124a and
the beacon interval, the processor 123a determines whether or not a
TBTT arrives. When it is determined that the TBTT arrives, the
process proceeds to step S14. Note that when the wireless module
12a operates in the sleep mode, the wireless module 12a returns to
the normal mode from the sleep mode in response to an arrival of
the TBTT (strictly speaking, the wireless module 12a returns to the
normal mode from the sleep mode immediately prior to the TBTT).
[0082] In step S14, the processor 123a determines whether or not
the currently arriving TBTT is a twelfth TBTT counting from when
the TBTT interrupt signal is most recently outputted. When it is
determined that the currently arriving TBTT is the twelfth TBTT,
the process proceeds to step S16. On the other hand, when it is
determined that the currently arriving TBTT is not the twelfth
TBTT, the process proceeds to step S18. As a method of determining
whether or not the currently arriving TBTT is the twelfth TBTT
counting from when the TBTT interrupt signal is most recently
outputted, a counter may be prepared in the storage section 122a so
as to count the number of times the TBTT arrives from when the TBTT
interrupt signal is most recently outputted. Then, the counter may
count up each time the TBTT arrives, and the counter may be reset
when the TBTT interrupt signal is newly outputted.
[0083] In step S16, the processor 123a outputs the TBTT interrupt
signal to the interrupt circuit 16a.
[0084] In step S18, the processor 123a outputs another beacon
signal via the wireless section 121a.
[0085] In step S20, via the wireless section 121a, the processor
123a transmits to the second game apparatus 10b the operation
information about the first game apparatus 10a which is stored in
the storage section 122a by the game processing section 14a, and
receives the operation information about the second game apparatus
10b from the second game apparatus 10b and stores the received
operation information about the second game apparatus 10b in the
storage section 122a, in accordance with a predetermined procedure.
Thereafter, the wireless module 12a shifts to the sleep mode and
the process returns to step S12.
[0086] In the present embodiment, a transmission cycle of the
beacon signal is synchronized to the game processing cycle, and the
operation information is exchanged between the two wireless modules
at the beacon interval. Therefore, each of the two wireless modules
can obtain most recent operation information about the other
communication party in each game processing cycle, and thus it is
effective that a process can be executed based on the most recent
operation information in the each game processing cycle.
Furthermore, since each of the wireless modules recognizes the TBTT
(Target Beacon Transmit Time), times at which the operation
information is transmitted/received between the wireless modules
can be effectively synchronized to each other, thereby making it
possible to cause the wireless modules to be intermittently
operated in the sleep mode as appropriate.
[0087] A process from steps S12 to S20 is repeated in a cycle of
16.7 msec which is the transmission cycle of the beacon signal.
[0088] Next, in step S22, the processor 123b of the wireless module
12b acting as the client receives the beacon signal (which is
transmitted from the wireless module 12a in step S10) via the
wireless section 121b.
[0089] In step S24, the processor 123b sets the value of the TSF
timer 124b based on the TSF timer value included in the beacon
signal received in step S22.
[0090] In step S26, based on the value of the TSF timer 124b and
the beacon interval included in the beacon signal received in step
S20, the processor 123b determines whether or not a TBTT arrives.
When it is determined that the TBTT arrives, the process proceeds
to step S28. Note that when the wireless module 12b operates in the
sleep mode, the wireless module 12b returns to the normal mode from
the sleep mode in response to the arrival of the TBTT (strictly
speaking, the wireless module 12b returns to the normal mode from
the sleep mode immediately prior to the TBTT).
[0091] In step S28, the processor 123b determines whether or not
the currently arriving TBTT is a twelfth TBTT counting from when
the TBTT interrupt signal is most recently outputted. When it is
determined that the currently arriving TBTT is the twelfth TBTT,
the process proceeds to step S30. On the other hand, when it is
determined that the currently arriving TBTT is not the twelfth
TBTT, the process proceeds to step S32.
[0092] In step S30, the processor 123b outputs the TBTT interrupt
signal to the interrupt circuit 16b.
[0093] In step S32, the processor 123b receives the said another
beacon signal (which is transmitted from the wireless module 12a in
step S18) via the wireless section 121b.
[0094] In step S34, based on the TSF timer value included in the
said another beacon signal received in step S32 (the value of the
TSF timer 124a obtained when the wireless module 12a transmits the
said another beacon signal in step S18), the processor 123b updates
the value of the TSF timer 124b, thereby correcting a difference
between the TSF timer 124a and the TSF timer 124b.
[0095] In step S36, via the wireless section 121b, the processor
123b receives the operation information about the first game
apparatus 10a from the first game apparatus 10a and stores the
received operation information about the first game apparatus 10a
in the storage section 122b, and transmits to the first game
apparatus 10a the operation information about the second game
apparatus 10b which is stored in the storage section 122b by the
game processing section 14b, in accordance with a predetermined
procedure. Thereafter, the wireless module 12b shifts to the sleep
mode and the process returns to step S26.
[0096] A process from steps S26 to S36 is repeatedly executed in a
cycle of 16.7 msec which is the transmission cycle of the beacon
signal.
[0097] Next, with reference to a flowchart shown in FIG. 5, the
flow of the main process executed by the game processing section
14a and the game processing section 14b will be described.
[0098] In step S40, the game processing section 14a of the first
game apparatus 10a acting as the master sets an interval of a
beacon signal to be outputted from the wireless module 12a to a
time period N times as long as the game processing cycle (16.7 msec
in the present embodiment).
[0099] In step S42, the game processing section 14a shares the
operation information between the first game apparatus 10a and the
second game apparatus 10b. Specifically, the game processing
section 14a stores the operation information about the first game
apparatus 10a in a transmission buffer (the storage section 122a)
of the wireless module 12a, and obtains the operation information
about the second game apparatus 10b stored in a reception buffer
(the storage section 122a).
[0100] In step S44, based on the operation information shared in
step S42 between the first game apparatus 10a and the second game
apparatus 10b, the game processing section 14a executes the game
processing. For example, when a first character operated by the
player of the first game apparatus 10a and a second character
operated by the player of the second game apparatus 10b exist in a
shared virtual game space, the game processing section 14a controls
the first character based on the operation information about the
first game apparatus 10a and controls the second character based on
the operation information about the second game apparatus 10b.
[0101] In step S46, the game processing section 14a determines
whether or not the interrupt circuit 16a outputs a V blank
interrupt signal as the interrupt request signal. When it is
determined that the V blank interrupt signal is outputted, the
process proceeds to step S48. On the other hand, when it is
determined that the V blank interrupt signal is not yet outputted,
the game processing in step S44 continues until the V blank
interrupt signal is outputted. Note that when the V blank
interruption occurs even in the middle of the game processing in
step S44, the game processing in step S44 is stopped and the
process proceeds to step S48.
[0102] In step S48, the game processing section 14a generates game
image data reflecting a result of the game processing in step S44
and writes the game image data into the flame buffer 26a.
Thereafter, the process returns to step S42.
[0103] A process from steps S42 to S48 is repeatedly executed in a
cycle of 16.7 msec which is the game processing cycle of the game
processing section 14a (in the present embodiment, the game
processing cycle of the game processing section 14a is equivalent
to a cycle in which the display screen of the display section 18a
is updated).
[0104] Next, in step S50, the game processing section 14b of the
second game apparatus 10b acting as the client shares the operation
information between the first game apparatus 10a and the second
game apparatus 10b. Specifically, the game processing section 14b
stores the operation information about the second game apparatus
10b in a transmission buffer (the storage section 122b) of the
wireless module 12b, and obtains the operation information about
the first game apparatus 10a stored in a reception buffer (the
storage section 122b).
[0105] In step S52, based on the operation information shared in
step S50 between the first game apparatus 10a and the second game
apparatus 10b, the game processing section 14b executes the game
processing. For example, when the first character operated by the
player of the first game apparatus 10a and the second character
operated by the player of the second game apparatus 10b exist in
the shared virtual game space, the game processing section 14b
controls the first character based on the operation information
about the first game apparatus 10a and controls the second
character based on the operation information about the second game
apparatus 10b.
[0106] In step S54, the game processing section 14b determines
whether or not the interrupt circuit 16b outputs a V blank
interrupt signal as the interrupt request signal. When it is
determined that the V blank interrupt signal is outputted, the
process proceeds to step S56. On the other hand, when it is
determined that the V blank interrupt signal is not yet outputted,
the game processing in step S52 continues until the V blank
interrupt signal is outputted. Note that when the V blank
interruption occurs even in the middle of the game processing in
step S52, the game processing in step S52 is stopped and the
process proceeds to step S56.
[0107] In step S56, the game processing section 14b generates game
image data reflecting a result of the game processing in step S52
and writes the game image data into the flame buffer 26b.
Thereafter, the process returns to step S50.
[0108] A process from steps S50 to S56 is repeatedly executed in a
cycle of 16.7 msec which is the game processing cycle of the game
processing section 14b (in the present embodiment, the game
processing cycle of the game processing section 14b is equivalent
to a cycle in which the display screen of the display section 18b
is updated).
[0109] Note that when the interrupt circuit 16a outputs the
interrupt request signal, the game processing section 14a suspends
the aforementioned main process so as to execute the interrupt
process (the TBTT interrupt process or the V blank interrupt
process) in response to the interrupt request signal. The same is
also true of the game processing section 14b.
[0110] In the TBTT interrupt process, as shown in FIG. 6, the game
processing section 14a reads the value of the V counter 181a
obtained when the TBTT interrupt signal is outputted, and stores
the value thus obtained as the V counter value at TBTT in the
storage section 24a. The same is also true of the game processing
section 14b.
[0111] In the V blank interrupt process, as shown in FIG. 7, based
on the V counter value at TBTT stored in the storage section 24a
when the TBTT interrupt process is most recently executed, the game
processing section 14a updates the value of the V counter 181a. A
detailed process of updating the value of the V counter 181a has
been described above. The same is also true of the game processing
section 14b.
[0112] As described above, in the present embodiment, based on the
TBTT interrupt signal outputted from each of the wireless module
12a and the wireless module 12b in a cycle N times as long as the
game processing cycle, the first game apparatus 10a and the second
game apparatus 10b adjust the V counter 181a and the V counter
181b, respectively, thereby making it possible to synchronize the
game processing executed by the first game apparatus 10a and the
game processing executed by the second game apparatus 10b.
[0113] Particularly, the wireless module 12a and the wireless
module 12b can be realized simply by adding a slight change (i.e.,
adding a function of outputting the TBTT interrupt signal) to a
conventional wireless module which complies with the wireless LAN
standard IEEE802.11, thereby making it possible to achieve the
present invention at a low cost.
[0114] Furthermore, the game processing cycles of the game
processing sections 14a and 14b coincide with communication cycles
(cycles in which the operation information is transmitted/received)
of the wireless modules 12a and 12b, respectively. Therefore,
unlike the conventional art, there is no need to create the game
program taking into consideration differences between the game
processing cycles of the game processing sections 14a and 14b and
the communication cycles of the wireless modules 12a and 12b,
respectively. Thus, it becomes possible to reduce troublesome tasks
required for a programming work performed by a programmer.
[0115] Although the present embodiment illustrates an example where
the wireless module 12a (the wireless module 12b) operates in the
sleep mode for a time period from when the operation information is
transmitted/received to when the TBTT subsequently arrives, the
present invention is not limited thereto.
[0116] Although the present embodiment illustrates an example where
the wireless module 12a (the wireless module 12b) complies with the
wireless LAN standard IEEE802.11, the present invention is not
limited thereto. Any wireless module having the TSF (a function of
synchronizing timers provided inside the wireless modules) can be
used. For example, a wireless module which complies with a standard
such as Bluetooth (registered trademark) or Zigbee (registered
trademark) can be used.
[0117] Although the present embodiment illustrates an example where
the game processing cycle is synchronized to a cycle in which the
display screen is updated, the present invention is not limited
thereto. The game processing cycle may be different from the cycle
in which the display screen is updated. In this case, the first
game apparatus 10a (the second game apparatus 10b) needs to
include, other than the V counter 181a (the V counter 181b), a game
processing cycle counter for measuring the game processing cycle,
and the game processing section 14a (the game processing section
14b) may adjust the game processing cycle counter based on a time
at which the TBTT interrupt signal is outputted.
[0118] Although the present embodiment illustrates and example
where the operation information is transmitted/received in a cycle
of 16.7 msec, the present invention is not limited thereto. In the
case where an operation performed by the player needs to be
instantly reflected in the game processing such as an action game,
for example, it is desirable that the operation information is
frequently transmitted/received. On the contrary, in the case where
the operation performed by the player does not need to be instantly
reflected in the game processing such as a table game, it is not
necessary to transmit/receive the operation information as
frequently as the action game.
[0119] Although the present embodiment illustrates an example where
the value of the V counter 181a (the V counter 181b) is adjusted so
as to become close to "0" when the TBTT interrupt signal is
outputted, the present invention is not limited thereto. The value
of the V counter 181a (the V counter 181b) may be adjusted so as to
become close to a specified value other than "0" when the TBTT
interrupt signal is outputted.
[0120] The present embodiment illustrates an example where the game
processing cycle is 16.7 msec. However, this is merely an example
and the present invention is not limited thereto.
[0121] Although the present embodiment illustrates an example where
the value of the V counter 181a (the V counter 181b) is adjusted
based on the TBTT interrupt signal outputted from the wireless
module 12a (the wireless module 12b) in response to the arrival of
the TBTT, the present invention is not limited thereto. For
example, irrespective of the arrival of the TBTT, the processor
123a (the processor 123b) of the wireless module 12a (the wireless
module 12b) may output an interrupt signal (conveniently referred
to as a "TSF timer interrupt signal") in a cycle N times as long as
the game processing cycle based on the TSF timer 124a (the TSF
timer 124b), and the game processing section 14a (the game
processing section 14b) may adjust the value of the V counter 181a
(the V counter 181b) based on the TSF timer interrupt signal. In
this case, the transmission interval of the beacon signal can be
freely set irrespective of the game processing cycle. However, in
this case, a counter for outputting the TSF timer interrupt signal
in a predetermined cycle needs to be additionally prepared.
[0122] Furthermore, in an example shown in FIG. 2, the wireless
module 12a acting as the master outputs the TBTT interrupt signal
at the same time as the wireless module 12b acting as the client.
However, the wireless module 12a does not need to output the TBTT
interrupt signal at the same time as the wireless module 12b. As
shown in FIG. 8, for example, 16.7 msec after the wireless module
12a outputs the TBTT interrupt signal, the TBTT interrupt signal
may be outputted from the wireless module 12b.
[0123] The wireless module 12a and the wireless module 12b may not
only have an operation mode for outputting the TBTT interrupt
signal (tentatively referred to as a "local game mode"), as
described in the present invention, but also have a function of
operating in an infrastructure mode or an ad hoc mode, which are
operation modes of a general wireless communication module (the
TBTT interrupt signal is not outputted in the infrastructure mode
or the ad hoc mode). In this case, each of the wireless module 12a
and the wireless module 12b switches the aforementioned operation
modes between each other based on an instruction outputted from
each of the game processing section 14a and the game processing
section 14b.
[0124] Note that the infrastructure mode or the ad hoc mode are
terms used in the wireless LAN standard IEEE802.11, and therefore
the descriptions thereof will be omitted. The aforementioned local
game mode is a mode in which the ad hoc mode is customized to be
used for a communication game.
[0125] Furthermore, the present embodiment illustrates an example
where the interrupt circuit 16a outputs the TBTT interrupt signal
to the game processing section 14a, thereby causing the game
processing section 14a to execute the adjustment process of
adjusting the V counter 181a. However, by additionally providing an
adjustment circuit, the interrupt circuit 16a may output the TBTT
interrupt signal to the adjustment circuit, thereby causing the
adjustment circuit to execute the adjustment process of adjusting
the V counter 181a. The adjustment circuit may be provided inside
or outside the wireless module 12a. Alternatively, the interrupt
circuit 16a may be provided inside the wireless module 12a. Still
alternatively, the interrupt circuit 16a may output the TBTT
interrupt signal to the processor 123a of the wireless module 12a,
thereby causing the processor 123a to execute the adjustment
process of adjusting the V counter 181a.
[0126] Furthermore, the game processing section 14a and/or the
display section 18a may execute a predetermined process in a cycle
of 16.7 msec based on the TSF timer 124a (by reading the TSF timer
124a or in response to an interrupt request outputted based on the
TSF timer value) (in this case, the clock 20a or the V counter 181a
are not necessary).
[0127] Still furthermore, each of the game processing section 14a
and the display section 18a may not execute a process in a
predetermined cycle. Specifically, in the case where a time at
which the game processing section 14a of the first game apparatus
10a executes the process needs to coincide with a time at which the
game processing section 14b of the second game apparatus 10b
executes the process, and/or in the case where a time at which the
display section 18a of the first game apparatus 10a executes the
process needs to coincide with a time at which the display section
18b of the second game apparatus 10b executes the process, it can
be achieved by causing each of the game apparatuses 10a and 10b to
determine, based on its own TSF timer value (or based on its own V
counter value adjusted in accordance with the TSF timer value), the
time at which each of the game processing section 14a or 14b
executes the process and/or the time at which each of the display
section 18a or 18b executes the process.
[0128] Still furthermore, the present embodiment illustrates an
example where one flame buffer 26a is provided. However, the
present invention is applicable as a game apparatus in which a
plurality of flame buffers 26a are provided and the plurality of
flame buffers 26a are used by switching therebetween so as to be
synchronized to the cycle in which the display section 18a updates
the display screen. In this case, the game processing section 14a
switches a flame buffer used by the display section 18a (a flame
buffer which stores the image data to be outputted to the screen of
the display section 18a) from one to another during the V blank
period (specifically, when step S48 or the like is executed). In
this case, not even during the V blank period, the game processing
section 14a writes the image data into the flame buffer 26a not
currently used by the display section 18a, thereby making it
possible to update the game image.
[0129] Although the present embodiment illustrates an example where
the V counter 181a (the V counter 181b) is adjusted based on the
TBTT interrupt signal outputted from the wireless module 12a (the
wireless module 12b), the present invention is not limited thereto.
The V counter 181a (the V counter 181b) may be adjusted without
using an interrupt signal outputted from the wireless module 12a
(the wireless module 12b). Hereinafter, an example where the V
counter is adjusted by polling without using the interrupt signal
will be described as a second embodiment.
Second Embodiment
[0130] FIG. 9 is a block diagram illustrating the configuration of
the game system according to the second embodiment of the present
invention. The configuration shown in FIG. 9 is similar to that
shown in FIG. 1 except that the TBTT interrupt signals are not
outputted from the processors 123a and 123b to the interrupt
circuits 16a and 16b, respectively, and therefore a detailed
description thereof as shown in FIG. 9 will be omitted.
[0131] According to the second embodiment, as shown in FIG. 10, the
game processing section 14a obtains the value of the TSF timer 124a
(the TSF timer value) of the wireless module 12a on a regular basis
in a cycle N times as long as 16.7 msec, thereby adjusting the V
counter 181a based on the TSF timer value thus obtained. The same
is also true of the game processing section 14b.
[0132] Hereinafter, described will be the flows of the processes
executed by the game processing section 14a, the game processing
section 14b, the wireless module 12a and the wireless module 12b
when executing the game in accordance with the game program loaded
to the storage section 24a (the storage section 24b) from the game
cartridge 30a (the game cartridge 30b).
[0133] FIG. 11 is a flowchart illustrating the flow of the process
executed by the wireless module 12a and the wireless module 12b
will be described. Note that the process shown in FIG. 11 is
similar to that shown in FIG. 4 except that a process which
pertains to transmission of the TBTT interrupt signal (i.e.,
processes of steps S14, S16, S28 and S30 which are shown in FIG. 4)
is deleted, and therefore a detailed description thereof as shown
in FIG. 11 will be omitted.
[0134] Note that prior to step S10, the first game apparatus 10a
acting as the master previously adjusts the value of the V counter
181a such that the TSF timer value becomes equal to a natural
number multiple of the game processing cycle at the time of the V
blank interruption (i.e., at a time when the value of the V counter
181a becomes "192" in the present embodiment). The same is also
true of the second game apparatus 10b acting as the client.
[0135] According to the second embodiment, the flow of the main
process executed by the game processing section 14a and the game
processing section 14b is the same as that in the first embodiment
(see FIG. 5). Note that in the first embodiment, the transmission
interval of the beacon signal is set N times as long as the game
processing cycle. However, in the second embodiment where the TBTT
interrupt signal is not used, the transmission interval of the
beacon signal may be set freely.
[0136] Note that when the interrupt circuit 16a outputs an
interrupt request signal, the game processing section 14a suspends
the aforementioned main process so as to execute an interrupt
process (the V blank interrupt process) in response to the
interrupt request signal. The same is also true of the game
processing section 14b.
[0137] FIG. 12 is a flowchart illustrating a detail of the V blank
interrupt process. In step S70, the game processing section 14a
determines whether or not the currently executed V blank interrupt
process is a twelfth V blank interrupt process counting from when
the value of the V counter 181a is most recently updated. When it
is determined that the currently executed V blank interrupt process
is the twelfth V blank interrupt process, the process proceeds to
step S72. On the other hand, when it is determined that the
currently executed V blank interrupt process is not the twelfth V
blank interrupt process, the V blank interrupt process is finished.
In step S72, the game processing section 14a obtains the value of
the TSF timer 124a obtained when the twelfth V blank interrupt
process is executed as the TSF timer value. In step S74, the game
processing section 14a calculates a remainder by dividing the TSF
timer value (in msec) obtained in step S72 by 16.7 msec which is
the game processing cycle. In step S76, the game processing section
14a updates the value of the V counter 181a based on the remainder
calculated in step S74.
[0138] Hereinafter, processes of steps S74 and S76 will be
described in detail.
[0139] The game processing section 14a calculates a difference
between the remainder calculated in step S74 and a predetermined
ideal value ("0" in the present embodiment, for example), thereby
increasing or decreasing the value of the V counter 181a based on
the difference such that the remainder calculated in step S74
becomes close to the predetermined ideal value.
[0140] For example, the TSF timer value obtained in step S72 is
200.6 msec, a remainder calculated in step S74 is 0.2 msec from an
expression 200.6 msec=16.7 msec.times.12+0.2 msec. In the present
embodiment, the V counter 181a counts from "0" to "262" during 16.7
msec which is the game processing cycle. Therefore, from an
expression 263.times.0.2 msec/16.7 msec=3.1, 0.2 msec corresponds
to approximately three counts of the V counter 181a (three scanning
lines). Thus, in step S76, the game processing section 14a
subtracts "3" from the value of the V counter 181a.
[0141] Alternatively, for example, the TSF timer value obtained in
step S72 is 249.8 msec, a remainder calculated in step S72 is 16.0
msec from an expression 249.8 msec=16.7 msec.times.14+16.0 msec.
From an expression 263.times.16.0 msec/16.7 msec=252.0, 16.0 msec
corresponds to approximately 252 counts of the V counter 181a (252
scanning lines). This indicates that if the value of the V counter
181a counts up by "11" (=263-252), a remainder calculated in step
S74 of the V blank interrupt process to be subsequently executed
will be substantially "0". Thus, in step S76, the game processing
section 14a adds "11" to the value of the V counter 181a.
[0142] When a value to be added/subtracted to/from the value of the
V counter 181a is greater than a predetermined value ("4", for
example), instead of adding/subtracting the value to/from the value
of the V counter 181a, the value of the V counter 181a may be
added/subtracted in a plurality of stages. On the other hand, when
the value to be added/subtracted to/from the value of the V counter
181a is smaller than a predetermined value ("2", for example), a
change in the value of the V counter 181a may be omitted.
[0143] By executing the aforementioned process, it becomes possible
to cause a time at which the V blank period starts to coincide with
a time at which the TSF timer 124a indicates a multiple of 16.7
msec. Therefore, it is assured that the game processing section 14a
executes the game processing in a cycle of 16.7 msec based on the
TSF timer 124a. Similarly, it is also assured that the game
processing section 14b executes the game processing in a cycle of
16.7 msec based on the TSF timer 124b. The TSF of each of the
wireless modules assures that the TSF timer 124a and the TSF timer
124b are synchronized to each other. As a result, the game
processing cycle of the game processing section 14a and the game
processing cycle of the game processing section 14b are also
synchronized to each other accordingly.
[0144] Although the present embodiment illustrates an example where
the value of the V counter is adjusted such that the remainder
calculated in step S74 shown in FIG. 12 becomes close to "0", the
present invention is not limited thereto. The value of the V
counter may be adjusted such that the remainder calculated in step
S74 shown in FIG. 12 becomes close to a specified value other than
"0".
[0145] Although the present embodiment illustrates an example where
the value of the V counter is adjusted based on the TSF counter
value obtained when the V blank period starts, the present
invention is not limited thereto.
[0146] Furthermore, in an example shown in FIG. 10, the game
processing section 14a of the first game apparatus 10a acting as
the master reads the TSF timer value at the same time as the game
processing section 14b of the second game apparatus 10b acting as
the client. However, the game processing section 14a does not need
to read the TSF timer value at the same time as the game processing
section 14b. For example, 16.7 msec after the game processing
section 14a of the first game apparatus 10a reads the TSF timer
124a, the game processing section 14b of the second game apparatus
10b may read the TSF timer 124b.
[0147] Although the present embodiment illustrates an example where
the value of the V counter 181a (the V counter 181b) is adjusted
every twelve times the V blank interrupt signal is outputted, the
present invention is not limited thereto. For example, the value of
the V counter 181a (the V counter 181b) may be adjusted each time
the V blank interrupt signal is outputted.
[0148] While the invention has been described in detail, the
foregoing description is in all aspects illustrative and not
restrictive. It is understood that numerous other modifications and
variations can be devised without departing from the scope of the
invention.
* * * * *